Forces governing the dynamics of liquid spreading in packed beds

Liquid spreading through a randomly packed particle-resolved bed influenced by capillary or inertial ( $AB_s \sim 1$ ), and gravitational force (moderately 0.1$ ) strongly 0.01$ )) is investigated using the volume-of-fluid simulations. The relative contribution of governing forces at different stages analysed time evolution Weber $We_I$ $AB_I$ numbers. We show that dynamics liquid primarily governed in beginning $AB_I > , $We_I followed $t/t^* . This interplay leads to inertia- capillary-induced bubble entrapments void scale promote lateral spreading. When $t/t^*$ for which flow < decreases substantial large ). balance unified-void filling characterised negligible trapping results decrease Further $AB_s$ ${\sim } with small very leading trickling further Finally, regime map proposed, provides relationship between forces, void-scale events, resultant